Handle SIGPIPE gracefully in top

top's output is sometimes redirected into a socket (ex: bugreport).
If that socket is then closed, top gets a SIGPIPE and crashes,
resulting in a tombstone.  Since this is a normal case, a tombstone is
not warranted.  It should just exit gracefully instead.

Change-Id: I0087401af36bfc72446d58b3043251ccd6884eda
Reviewed-on: http://gerrit.pcs.mot.com/536587
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Reviewed-by: Jeffrey Carlyle <jeff.carlyle@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>